Risks with OpenSSL verifying a signature with un-trusted PEM encoded public key

If a website user wants to use WebAuthn, they will start by creating a credential, where their authentication device provides a public key.

This key is encoded, and sent back to the server to store against their account.

Later, when the … Continue reading Risks with OpenSSL verifying a signature with un-trusted PEM encoded public key

Why does WebAuthn require a challenge when asking the client to register a new credential?

When registering a new credential as part of WebAuthn, why does the client need to be sent a challenge?

Presumably this is to prevent a replay attack, but wouldn’t a replay attack be prevented by TLS already?

Continue reading Why does WebAuthn require a challenge when asking the client to register a new credential?